Wilmington Looks to Us for Geothermal Heating & Cooling! We're O'Brien Service Company. And we're recognized throughout Wilmington, North Carolina, for our geothermal heating and cooling expertise. Residents look to us for ... superior geothermal system installation and service qualified, highly trained personnel who know every detail of geothermal heating and cooling - and know how to effectively communicate the process to you geothermal systems from one of the industry's most credible names - WaterFurnace recommendation on how to get the most from their geothermal heating and cooling installation Of course, a pivotal reason people look to us to begin with is for the savings they can realize on their energy bills with a geothermal system. Want a snap shot? Give our Geothermal Savings Calculator a go. Then push forward with the next step and contact O'Brien Service Company. We'll show you more of what makes geothermal systems the optimum choice for year-round heating and cooling comfort in Wilmington.